Diastereoisomers—Stereoisomers that are not mirror images of each other.

Electrophoresis—A chemical analysis technique that takes advantage of the differential movement of a charged substance under the influence of an electric field.

Enantiomers—Stereoisomers that are mirror images of each other. Enantiomers are optically active and rotate the plane of polarized light.

Epimer—A stereoisomer that has a different configuration at only one of several chiral carbon centers.

Extremophiles—Microorganisms capable of growing under extreme physiochemical conditions, such as high temperatures, pressures, and acidity.

Fischer-Tropsch (FT) process—A method for the synthesis of hydrocarbons and other carbon compounds. Typically, a mixture of hydrogen and carbon monoxide is reacted in the presence of an iron or cobalt catalyst to produce methane and other organic compounds, with water and carbon dioxide as by-products.

GC-MS—Gas chromatography-mass spectrometry.

Graben—A block of the crust, generally with length much greater than its width, that has dropped relative to the areas on either side because it is bordered by two faults.

GRS—Gamma-Ray Spectrometer.

HEND—High-Energy Neutron Spectrometer.

Hesperian—The martian geological epoch ranging from some 3.7 billion to 3 billion years ago. Regions that were formed in this era are characterized by extensive lava fields.

Isomer—One of two or more substances that have the same chemical composition but differ in structural form.

Kerogens—A family of chemical compounds that make up a portion of the organic matter found in sedimentary rocks. They are insoluble in organic solvents, non-oxidizing acids (HCI and HF), and bases because of their very high molecular weight. Each kerogen molecule is formed by the random combination of numerous monomers. When heated, hydrogen-rich kerogens yield crude oil, and hydrogen-poor kerogens yield mainly gas.

Labile—Easily reactive.

LC-MS—Liquid chromatography-mass spectrometry.

Macromolecules—Molecules with a high molecular mass, such as polymers.

Mars Express—A European Space Agency mission comprising an obiter mapping the surface and atmospheric composition and an unsuccessful lander, the Beagle 2. Mars Express has been orbiting Mars since late 2003.

Mars Odyssey—A NASA spacecraft launched in 2001. Odyssey is an orbiter looking for evidence of past or present water and mapping the mineralogical characteristics of the martian surface.

MAVEN—The Mars Atmosphere and Volatile Evolution mission, one of two candidates under consideration by NASA for the Mars Scout launch opportunity in 2011.

MEPAG—NASA’s Mars Exploration Program Analysis Group.

MER—NASA’s Mars Exploration Rover mission, which launched two rovers, Spirit and Opportunity, in 2003. Both rovers are equipped to image and analyze the martian landscape.

Metazoa—Multicellular organisms capable of locomotion.

Metaphytes—Multicellular plants.

MGS—NASA’s Mars Global Surveyor spacecraft, which has been orbiting Mars since 1996. Although the spacecraft completed its primary mission of mapping the martian surface in 2001, it continued to return important scientific data until it lost contact with Earth in November 2006.

Mid Rovers—A proposed Mars rover mission currently being studied as a candidate for launch in 2016 or 2018.



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